Introversion

If a crowded cocktail party feels like a holding cell to you, even as you gamely keep up your end of the chatter, chances are you're an introvert. Introverts are drained by social encounters and energized by solitary, often creative pursuits.

Extroversion

Extroverts make up about three-quarters of the American population, and as such come in all stripes. They zip through the world in search of novel experiences, social connections, and leadership opportunities.